My prior U.S. Pat. No. 4,026,336 is directed to a dispensing apparatus which is adaptable for use in permitting the isolated transfer of flowable materials between a supply container and a container to be filled and specifically in a manner which will permit sealed isolation of the materials in the supply or storage container both during transfer and when not in use. For instance, by way of illustration, that invention as well as the present invention is specifically adaptable for use in the dispensing of granular or powdered materials, such as, salt, pepper, sugar, flour and the like from a supply container into a number of shakers or small containers by the simple expedient of inserting the dispenser spout through the normally closed access opening of the shaker so as to simultaneously open the dispenser spout for flow of the materials from the supply container into the container to be filled. The subject of my prior patent is presently in commercial use and, briefly, discloses the utilization of a neck or spout on one container which matingly cooperates with an opening in the receiving container to establish externally isolated flow, the container with the pouring spout attached thereto being cooperative with a spring-loaded cap or other normally closed access opening in the other container. The neck or spout assembly is broadly comprised of telescoping or concentrically positioned, elongated hollow members, the inner member being stationary and having a closed outer end with at least one port or orifice through the sidewall near the closed end. The closed end has a wedge portion with inwardly directed, sloping surfaces for deflecting material flow into the ports. The other end of the inner member may be secured for extension into an existing opening in the container so that the interior of the container is in open communication through the port. The other elongated hollow member is slidable over the stationary member so as to be positioned in normally closed relation to the port, such as, by the urging of a spring or other biasing element and includes a stop for preventing further travel once the port closing position is obtained. Still another elongated hollow member can be attached in fixed relation to the stationary member as a shroud which forms a cylindrical chamber between it and the inner member for retaining the spring element as well as to provide an outer extension stop for the slidable member. The other container has an opening through one wall sized for passage of the inner hollow member on the neck or spout assembly while blocking passage of the outer sliding hollow member. The container to be filled also may include an internally mounted plug across the access opening which can be urged to an open position, for instance, when the dispensing spout is inserted through the access opening.
Numerous other devices employ some form of a movable or retractable sleeve which is spring-loaded and can be depressed by engagement with a container to be filled so as to open supply ports for transfer of material from one container to another. Representative of such devices are disclosed in U.S. patent to Pahl et al. U.S. Pat. No. 2,761,606, Sessions et al. U.S. Pat. No. 3,072,299, Diamond U.S. Pat. No. 3,240,430, Berning et al. U.S. Pat. No. 3,307,595, Schwartzman U.S. Pat. No. 3,370,909, Kajita U.S. Pat. No. 3,373,776, Tissot-Dupont U.S. Pat. No. 3,402,747, Leeds U.S. Pat. No. 3,476,507, Nigro U.S. Pat. No. 3,680,605 and Ayres U.S. Pat. No. 3,885,608. Still other representative patents are discussed in my hereinbefore U.S. Pat. No. 4,026,336.
It is highly desirable to provide for a dispenser spout which is of simplified construction and is usable on existing supply containers or can be easily retrofit for isolated transfer of flowable materials between containers, and will operate to seal the supply container when not in use; yet is capable of automatically sealing both containers during transfer of materials therebetween so as to greatly minimize contamination or loss due to spillage.